var vchar1 = "{";
var vchar2 = "}";
var vsearch = "";
var vstring = "TRYTOPUT{MYSTRING}HERE";
varpos1 = 0;
varpos2 = 0;

varpos1  = vstring.indexOf(vchar1); 
varpos2  = vstring.indexOf(vchar2, varpos1  ); 
vsearch = vstring.substring(varpos1+1, varpos2);

gs.print(vsearch);

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